Spirifer. MOLLUSCA. SPIRIFERA. 375 



in the sinus, which is smooth and angular, instead of being rounded and stri- 

 ated." — Mart. Derb. t. xxxvi. f. 2. — In Carboniferous Limestone, Derbyshire. 



4. S. oblatus. — Gibbose, transversely obovate, smooth, with an obtuse, 

 rather square, elevation along the middle ; beaks approximated.— Sower. Min. 

 Conch, t. cclxviii.— Carboniferous Limestone' 



5. S. glaber. — Nearly twice as wide as long, generally sharp-edged. — Mart. 

 Derb. t. xlviii. f. 9-10. — Sower. Min. Conch, cclxix., two upper fig. — In Car. 

 boniferous Limestone : — probably identical with the last. 



6. S. obtusus — Gibbose, transversely oval, very obscurely striated, with an 

 obtuse, rounded elevation along the middle ; beaks rather distant. — Sower. 

 Min. Conch, t. cclxix., two lower figures — In Carboniferous Limestone. 



7« S. striatus — Hinge-depression extending the whole breadth of the shell ; 

 longitudinal ribs numerous, unequal, branched, mesial ridge rounded. — Ano- 



mites striatis. Mart. Derb. t. xxiii Spir. striatus, Sower. Min. Conch. 



t. eclxx., and S. rotundatus, ib. t. cccclxi. f. 1 — Carboniferous Limestone. 



8. S. pinguis. — Gibbose, transversely obovate, with a straight back, longi- 

 tudinally sulcated, elevated in the middle ; sulci eight or nine on each side, 

 and one in the centre of the elevation — Sower. Min. Conch, t. eclxxi. — Car- 

 boniferous Limestone. 



9. S. acutus. — Valves convex, semicircular, with deep equal ribs, the me- 

 sial edge and furrow smooth ; hinge-space short ; beak of the perforated 

 valve prominent, incurved. — Anomites acutus, Mart. Pet. Derb. t. xlix. f. 15, 

 16. Spirifer minimus, Sower. Min. Conch, t. ccclxxvii. f. 1. — Carboniferous 

 Limestone. 



10. S. Waleottli Suborbicular, gibbose, with one large, rounded, elevated 



fold in the middle, and four smaller ones on each side — Soiuer. Min. Conch, 

 t. ccclxxvii. f. 2. In Lias. 



11. S. lineatus. — Gibbose, covered with numerous diverging sharp striae; 

 front semicircular, elevated in the middle ; from the elevation of the front 

 a convex band proceeds to the beak ; hinge-line long and straight ; beaks 

 rather distant — Sower. Min. Conch, t. ccccxcii. f. 1, 2. — In Carboniferous 

 Limestone. 



12. S. attenualus; — Convex, covered with numerous linear furrows, which 

 increase in number towards the margin ; front rounded, elevated in the mid- 

 dle, from each side of the elevation a deep furrow proceeds to the beak ; 

 sides produced, pointed ; hinge-line long, straight ; space between the beaks 



flat, with nearly parallel edges Sower. Min. Conch, t. ccccxciii. f. 3, 4, 5— 



In Carboniferous Limestone. 



13. S. bisidcatus — Semicircular, gibbose, longitudinally sulcated, elevated in 

 the middle, a deep furrow on each side the elevation ; hinge-line long, 

 straight ; beaks close — Sower. Min. Conch, t. ccccxciv — Carboniferous Lime- 

 stone. 



14. S. distans. — Semicircular, gibbose ; sides sulcated longitudinally ; front 

 elevated, elevation extending to the beaks, concave along the middle ; beaks 

 incurved, distant, the space between them curved, triangulai - . — Sower. Min- 

 Conch, t. ccccxciv. f. 3. — Carboniferous Limestone. 



15. S. rcsupinatus — Transversely oval, witli numerous longitudinal stria; 

 and distant marks of growth ; perforated valve slightly convex towards the 

 beaks, depressed towards the margin ; the other valve more convex ; mar- 



